Unstable Clusters Research Articles

Structural, electronic and magnetic properties of AunPt (n = 1−12) clusters in comparison with corresponding pure Aun+1 (n = 1−12) clusters

An all-electron scalar relativistic calculation on Au n Pt (n = 1−12) clusters has been performed by using density functional theory with the generalized gradient approximation at PW91 level. Our results reveal that all the lowest energy geometries of Au n Pt (n = 1−12) clusters may be generated by substituting Pt atom for one gold atom of the Au n+1 cluster at the highest coordinated site. Compared with corresponding pure Au n+1 cluster, the lowest energy geometries of Au n Pt clusters are distorted slightly and still keep the planar structures due to the strong scalar relativistic effect in small gold cluster. The Au-Pt bonds are stronger and most Au-Au bonds far from Pt atom are weaker than the corresponding Au-Au bonds in pure Au n+1 cluster. By substituting Pt atom for one gold atom of Au n+1 cluster at the highest coordinated site, the relatively stable and inactive odd-numbered Au n+1 cluster becomes the relatively unstable and reactive odd-numbered Au n Pt cluster, and the relatively unstable and reactive even-numbered Au n+1 cluster becomes the relatively stable and inactive even-numbered Au n Pt cluster chemically and electronically. All the Au n Pt clusters prefer low spin multiplicity. The even-numbered Au n Pt clusters are found to exhibit zero magnetic moment and the odd-numbered Au n Pt clusters are found to possess magnetic moment with the value of 1 μ B. The odd-even alterations of magnetic moments and electronic configurations for Au n Pt clusters are very obvious and may be simply understood in terms of the electron pairing effect.

(HL)2Fe6(NCMe)m]n+ (m = 0, 2, 4, 6; n = −1, 0, 1, 2, 3, 4, 6): An Electron-Transfer Series Featuring Octahedral Fe6 Clusters Supported by a Hexaamide Ligand Platform

Using a trinucleating hexaamide ligand platform, the all-ferrous hexanuclear cluster ((H)L)(2)Fe(6) (1) is obtained from reaction of 3 equiv of Fe(2)(Mes)(4) (Mes = 2,4,6-Me(3)C(6)H(2)) with 2 equiv of the ligand ((H)L)H(6). Compound 1 was characterized by X-ray diffraction analysis, (57)Fe Mössbauer, SQUID magnetometry, mass spectrometry, and combustion analysis, providing evidence for an S=6 ground state and delocalized electronic structure. The cyclic voltammogram of [((H)L)(2)Fe(6)](n+) in acetonitrile reveals a rich redox chemistry, featuring five fully reversible redox events that span six oxidation states ([((H)L)(2)Fe(6)](n+), where n=-1→4) within a 1.3 V potential range. Accordingly, each of these species is readily accessed chemically to provide the electron-transfer series [((H)L)(2)Fe(6)(NCMe)(m)][PF(6)](n) (m=0, n=-1 (2); m=2, n=1 (3); m=4, n=2 (4); m=6, n=3 (5); m=6, n=4 (6)). Compounds 2-6 were isolated and characterized by X-ray diffraction, (57)Fe Mössbauer and multinuclear NMR spectroscopy, and combustion analysis. Two-electron oxidation of the tetracationic cluster in 6 by 2 equiv of [NO](+) generates the thermally unstable hexacationic cluster [((H)L)(2)Fe(6)(NCMe)(m)](6+), which is characterized by NMR and (57)Fe Mössbauer spectroscopy. Importantly, several stepwise systematic metrical changes accompany oxidation state changes to the [Fe(6)] core, namely trans ligation of solvent molecules and variation in Mössbauer spectra, spin ground state, and intracluster Fe-Fe separation. The observed metrical changes are rationalized by considering a qualitative, delocalized molecular orbital description, which provides a set of frontier orbitals populated by Fe 3d electrons.

Neutron irradiation on AlGaN/GaN high electron mobility transistors on SiC substrates

Electrical properties of AlGaN/GaN high electron mobility transistors (HEMTs) on SiC substrates irradiated with low dose of neutron are reported. AlGaN/GaN HEMTs with 0.5×100 μm 2 gate were irradiated with a dose of 2.8×10 11 cm −2 neutrons and average energy of 9.8 MeV. 10% of drain-source current was reduced right after neutron exposure, but complete recovery of current was observed in 40 day storage at room temperature. This is attributed to self-annealing process which removes unstable mobile defect clusters created by neutron bombardment. Also, neutron damaged sample showed instant recovery under UV light exposure. Fully recovered device was irradiated again with same conditions of neutrons, and similar recovery behavior at room temperature was obtained.

Antigen presenting and effector cell cluster formation in BALB/c mice during mousepox: model studies*

The objective of this study was to access APC-effector cell cluster formation in genetically susceptible BALB/c (H-2(d) ) mice infected with highly virulent Moscow strain of ectromelia virus (ECTV-MOS) and estimate of lymphocyte activation based upon expression of CD62L and CD44 molecules. APC-effector cell clusters were obtained by enzymatic digestion from draining lymph nodes (DLNs) and spleens of BALB/c mice. We found that APCs infected with ECTV-MOS form unstable clusters with effector cells, and thus may diminish T-cell activation at the early stage of mousepox. Different types of effector cells including T-cell subsets (CD4(+) and CD8(+) ), B cells and polymorphonuclear cells colocalize within individual clusters. Increase in CD19(+) B cells within APC-effector cell clusters during severe clinical mousepox may reflect B-cell activation. Our studies indicated vigorous changes in APC-effector cell cluster formation in genetically susceptible BALB/c mice during mousepox (up to 2 weeks). ECTV-MOS can modulate APC interactions with effector cells and consequently may impair T-cell activation probably owing to unstable cluster formation and/or subsequent weak stimulation by infected APCs at the early stages of mousepox. This is the first report of APC-effector cell cluster formation in BALB/c mice during mousepox. It gives us a new light on the mutual cell-cell interactions and development of the immune response during ECTV-MOS infection.

Stable and Unstable Malaria Hotspots in Longitudinal Cohort Studies in Kenya

Infectious diseases often demonstrate heterogeneity of transmission among host populations. This heterogeneity reduces the efficacy of control strategies, but also implies that focusing control strategies on "hotspots" of transmission could be highly effective. In order to identify hotspots of malaria transmission, we analysed longitudinal data on febrile malaria episodes, asymptomatic parasitaemia, and antibody titres over 12 y from 256 homesteads in three study areas in Kilifi District on the Kenyan coast. We examined heterogeneity by homestead, and identified groups of homesteads that formed hotspots using a spatial scan statistic. Two types of statistically significant hotspots were detected; stable hotspots of asymptomatic parasitaemia and unstable hotspots of febrile malaria. The stable hotspots were associated with higher average AMA-1 antibody titres than the unstable clusters (optical density [OD] = 1.24, 95% confidence interval [CI] 1.02-1.47 versus OD = 1.1, 95% CI 0.88-1.33) and lower mean ages of febrile malaria episodes (5.8 y, 95% CI 5.6-6.0 versus 5.91 y, 95% CI 5.7-6.1). A falling gradient of febrile malaria incidence was identified in the penumbrae of both hotspots. Hotspots were associated with AMA-1 titres, but not seroconversion rates. In order to target control measures, homesteads at risk of febrile malaria could be predicted by identifying the 20% of homesteads that experienced an episode of febrile malaria during one month in the dry season. That 20% subsequently experienced 65% of all febrile malaria episodes during the following year. A definition based on remote sensing data was 81% sensitive and 63% specific for the stable hotspots of asymptomatic malaria. Hotspots of asymptomatic parasitaemia are stable over time, but hotspots of febrile malaria are unstable. This finding may be because immunity offsets the high rate of febrile malaria that might otherwise result in stable hotspots, whereas unstable hotspots necessarily affect a population with less prior exposure to malaria.

IMS–MS studies based on coupling a differential mobility analyzer (DMA) to commercial API–MS systems

Recent progress in adding a mobility dimension to preexisting API–MS systems without modifying the MS itself is discussed, based on inserting a differential mobility analyzer (DMA) as part of the MS's atmospheric pressure ion source. Design criteria leading to high DMA resolving power R and transmission efficiency η are discussed. Various DMA prototypes have been interfaced to several triple quadrupoles, a single quadrupole and a quadrupole-TOF, all demonstrating R > 50 and η > 50%. We obtain two-dimensional DMA–MS spectra of the multiply charged clusters formed in electrosprays of concentrated solutions of tetrahexylammonium bromide (A +Br −). These reveal systematic loss of (ABr)A + fragments from unstable multiply charged clusters, and provide mobility measurements in air on mass resolved ( ABr ) n ( A + ) z clusters with n > 100 and z up to 10. Well-defined bands of ions not individually resolved are clearly visible at considerably larger n and z values.

Different effects on triacylglycerol packaging to oil bodies in transgenic rice seeds by specifically eliminating one of their two oleosin isoforms

Expression of OLE16 and OLE18, two oleosin isoforms in oil bodies of rice seeds, was suppressed by RNA interference. Electron microscopy revealed a few large, irregular oil clusters in 35S::ole16i transgenic seed cells, whereas accumulated oil bodies in 35S::ole18i transgenic seed cells were comparable to or slightly larger than those in wild-type seed cells. Large and irregular oil clusters were observed in cells of double mutant seeds. These unexpected differences observed in oil bodies of 35S::ole16i and 35S::ole18i transgenic seeds were further analyzed. In comparison to wild-type plants, OLE18 levels were reduced to approximately 40% when OLE16 was completely eliminated in 35S::ole16i transgenic plants. In contrast, OLE16 was reduced to only 80% of wild-type levels when OLE18 was completely eliminated in 35S::ole18i transgenic plants. While the triacylglycerol content of crude seed extracts of 35S::ole16i and 35S::ole18i transgenic seeds was reduced to approximately 60% and 80%, respectively, triacylglycerol in isolated oil bodies was respectively reduced to 45% and 80% in accordance with the reduction of their oleosin contents. Oil bodies isolated from both 35S::ole16i and 35S::ole18i transgenic seeds were found to be of comparable size and stability to those isolated from wild-type rice seeds, although they were merely sheltered by a single oleosin isoform. The drastic difference between the triacylglycerol contents of crude seed extracts and isolated oil bodies from 35S::ole16i transgenic plants could be attributed to the presence of large, unstable oil clusters that were sheltered by insufficient amounts of oleosin and therefore could not be isolated together with stable oil bodies.

Phase-field modeling of gas bubbles and thermal conductivity evolution in nuclear fuels

A phase-field model was developed to simulate the accumulation and transport of fission products and the evolution of gas bubble microstructures in nuclear fuels. The model takes into account the generation of gas atoms and vacancies, and the elastic interaction between diffusive species and defects as well as the inhomogeneity of elasticity and diffusivity. The simulations show that gas bubble nucleation is much easier at grain boundaries than inside grains due to the trapping of gas atoms and the high mobility of vacancies and gas atoms in grain boundaries. Helium bubble formation at unstable vacancy clusters generated by irradiation depends on the mobilities of the vacancies and He, and the continuing supply of vacancies and He. The formation volume of the vacancy and He has a strong effect on the gas bubble nucleation at dislocations. The effective thermal conductivity strongly depends on the bubble volume fraction, but weakly on the morphology of the bubbles.

An Iron-Sulfur Cluster Domain in Elp3 Important for the Structural Integrity of Elongator

The Elongator complex functions in diverse cellular processes, such as RNA polymerase II transcription and tRNA modification. The Elp3 subunit possesses a C-terminal histone acetyltransferase (HAT) domain and an N-terminal sequence that resembles an iron-sulfur (FeS) cluster motif. The HAT domain is well characterized, but the role of the FeS cluster is unknown, although one report proposed that it might be involved in catalyzing histone demethylation. We investigated the importance and function of the yeast Elp3 FeS cluster by a combination of genetic and biochemical means. To minimize oxidation of the Elp3 FeS cluster during purification, we also developed a novel tandem affinity tag and an accompanying isolation procedure that enables purification of tagged proteins to virtual homogeneity within a few hours of cell disruption. Our results failed to support a role for Elongator in histone demethylation. Moreover FeS cluster integrity was not required for the HAT or RNA binding activities of Elongator. However, a fully functional FeS cluster was required for Elongator integrity and for the association of the complex with its accessory factors Kti11 and Kti12. In contrast, the association of Elongator with RNA polymerase II in chromatin was unaffected by FeS cluster mutations. Together our data support the idea that the Elp3 FeS cluster is essential for normal Elongator function in vivo primarily as a structural, rather than catalytic, domain.

Vibrational spectroscopy of size-selected neutral and cationic clusters combined with vacuum-ultraviolet one-photon ionization detection

Various vibrational spectroscopic techniques combined with vacuum-ultraviolet one-photon ionization mass spectrometry have recently been developed for jet-cooled molecules and clusters. These techniques open general applications of size-selected infrared and also Raman spectroscopies to neutral clusters by overcoming difficulties in the conventional vibrational spectroscopic methods for jet-cooled clusters. Their spectroscopic principles have been demonstrated by investigations for neutral clusters of simple protic molecules without an ultraviolet chromophore, which is necessary for the conventional vibrational spectroscopic methods of gas phase clusters based on the fluorescence or multiphoton ionization detection. In addition, the vacuum-ultraviolet photoionization detection scheme enables us to perform infrared predissociation spectroscopy of unstable cluster cations such as unprotonated cluster cations of protic molecules. In this Perspective, the spectroscopic principles and their applications for neutral and cationic clusters are reviewed.

Stabilization of Fully Reduced Iron−Sulfur Clusters by Carbene Ligation: The [FenSn]0 Oxidation Levels (n = 4, 8)

The all-ferrous [Fe4S4](0) state has been demonstrated in the fully reduced Fe protein of the Azotobacter vinelandii nitrogenase complex. We seek synthetic analogues of this state more tractable than the recently prepared but highly unstable cluster [Fe4S4(CN)4](4-) (Scott, Berlinguette, Holm, and Zhou, Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 9741). The N-heterocyclic carbene 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene (Pr(i)2NHCMe2) has been found to stabilize the fully reduced clusters [Fe8S8(Pr(i)2NHCMe2)6] (4) and [Fe4S4(Pr(i)2NHCMe2)4] (5), which are prepared by cluster assembly or phosphine substitution of FenSn (n = 8, 16) clusters. Cluster 4 is also obtained by reaction of the carbene with all-ferrous [Fe7S6(PEt3)5Cl2] (3) and cluster 5 by carbene cleavage of 4. Detailed structures of 3 (monocapped prismatic), 4, and 5 are described; the latter two are the first iron-sulfur clusters with Fe-C sigma bonds. Cluster 4 possesses the [Fe8(mu3-S) 6(mu4-S)2] edge-bridged double cubane structure and 5 the cubane-type [Fe4(mu3-S)4] stereochemistry. The all-ferrous formulations of the clusters are confirmed by X-ray structure parameters and (57)Fe isomer shifts. Both clusters are stable under conventional aprotic anaerobic conditions, enabling further study of reactivity. The collective properties of 5 indicate that it is a meaningful synthetic analogue of the core of the fully reduced protein-bound cluster.

Phthalocyanine Nanoparticle Formation in Supersaturated Solutions

Self-organization of molecules in solution is an important natural and synthetic process, in particular for the preparation of nanomaterials. However, the mechanism of growth for solution-based nanoparticle formation is not always well understood. We present results that clarify these mechanisms in solutions of magnesium phthalocyanine in which the self-organization is induced by addition of a miscible nonsolvent. From simultaneous measurements of the sizes of the growing nanoparticles by photon correlation spectroscopy and the molecular concentration by absorption and fluorescence spectroscopy, we have found that the particles do not grow by molecular diffusion to the surfaces. These results suggest the importance of unstable clusters in the growth process. We also observed a strong dependence of the particle size on the initial concentration which we attribute to effects of the curvature of the solubility curve.

An extended master-equation approach applied to aggregation in freeway traffic

We restudy the master-equation approach applied to aggregation in a one-dimensional freeway, where the decay transition probabilities for the jump processes are reconstructed based on a car-following model. According to the reconstructed transition probabilities, the clustering behaviours and the stochastic properties of the master equation in a one-lane freeway traffic model are investigated in detail. The numerical results show that the size of the clusters initially below the critical size of the unstable cluster and initially above that of the unstable cluster all enter the same stable state, which also accords with the nucleation theory and is known from the result in earlier work. Moreover, we have obtained more reasonable parameters of the master equation based on some results of cellular automata models.

Photochemically induced nucleation in supersaturated and undersaturated thaumatin solutions

We demonstrate photochemically induced nucleation in supersaturated and undersaturated solutions of thaumatin. The irradiation of supersaturated and undersaturated thaumatin solutions in 0.75 M potassium sodium tartrate (PST) at pH 5.6 in N-(2-acetamido)iminodiacetic acid (ADA) buffer with β = 2 or β = 0.5 increased the number of thaumatin crystals in the droplet. The photochemical reaction induced the formation of unstable small clusters, which led to the growth of nuclei. The mechanism of nucleation enhancement was investigated in steady state and transient absorption experiments. The photochemical intermediate, in which one tryptophan residue is changed to a neutral tryptophanyl radical, appears to be responsible for the nucleation of thaumatin, as well as for the photochemically induced nucleation of lysozyme.

The influence of Ag+ ions on transformations of silver clusters in polyacrylate aqueous solutions

It is shown that transformations of unstable clusters, intermediates of the borohydride reduction of silver cations, in weakly alkaline polyacrylate aqueous solutions are governed by the competition between the processes of their oxidation, coalescence into larger particles, and reduction of silver cations. Moreover, these processes depend on the loading of a polyanion with cations and can be controlled by the addition of Ag+ ions.

Ligand chelation, P–C bond cleavage, and phenyl-group transfer in the reaction between RCCo 3(CO) 9 and 1,8-bis(diphenylphosphino)naphthalene (dppn): Syntheses and X-ray diffraction structures of PhCCo 3(CO) 4(μ-CO) 3(dppn) and PhCCo 3(CO) 8[η 1-PPh(OH)C 10H 6P(O)Ph 2

The tricobalt cluster PhCCo 3(CO) 9 ( 1) undergoes facile ligand substitution with 1,8-bis(diphenylphosphino)naphthalene (dppn) under thermal and Me 3NO activation to afford the cluster compounds PhCCo 3(CO) 8[PPh 2(1-C 10H 7)] ( 2) and PhCCo 3(CO) 4(μ-CO) 3(dppn) ( 3). Whereas thermolysis of dppn with the methylidyne-capped cluster HCCo 3(CO) 9 ( 4) yields only HCCo 3(CO) 8[PPh 2(1-C 10H 7)] ( 5) and HCCo 3(CO) 4(μ-CO) 3(dppn) (6) as isolable products, the reaction between 4 and dppn in the presence of Me 3NO furnishes the latter two clusters in addition to the phenyl-capped cluster PhCCo 3(CO) 8[η 1-PPh(OH)C 10H 6P(O)Ph 2] ( 7). The clusters 2 and 5 represent simple substitution products based on the ligand diphenyl(1-naphthyl)phosphine, while clusters 3 and 6 each possess a chelating dppn ligand and three bridging CO groups in the solid state. Oxidation of the two phosphine moieties by Me 3NO and transfer of one of the phenyl groups from the dppn ligand to the methylidyne carbon moiety in cluster 4 produces the thermally unstable cluster 7. These clusters have been characterized in solution by IR and 31P NMR spectroscopies, and the solid-state structures of 3 and 7 established by X-ray crystallography.

The night driving behavior in a car-following model

In this paper, we have studied the night driving behaviors in the car-following model in periodic boundary conditions. The evolution of uniform traffic under both small and large perturbations is investigated. The simulations show that the traffic is always unstable when V ′ < 0 with V the optimal velocity. The traffic clusters, the kink–antikink waves, and the unstable clusters are observed under different sensitivity parameters. Even more interesting phenomenon is observed when the randomness effect is considered. Under large perturbations, it is shown that the traffic will be unstable if its density is smaller than a threshold. The density corresponding to the threshold increases with the decrease of the sensitivity parameter values.

Ligand substitution in the tetrahedrane clusters RCCo 2Mo(η 5-indenyl)(CO) 8 with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd): Influence of the carbyne and indenyl ligands on the stability of the substitution products and X-ray diffraction structures of HCCo 2Mo(η 5-indenyl)(CO) 6(μ-bpcd) and CoMo(η 5-indenyl)(μ-CPh)(CO) 2(μ-bpcd)Cl

The ligand substitution behavior of the tetrahedrane clusters RCCo 2Mo(η 5-indenyl)(CO) 8 [R = H ( 1); Ph ( 3)] with the diphosphine ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) has been investigated. Thermolysis of cluster 1 with bpcd in CH 2Cl 2, 1,2-dichloroethane, or toluene affords the bpcd-bridged cluster HCCo 2Mo(η 5-indenyl)(CO) 6(μ-bpcd) ( 2) as the initial product. Cluster 2 is unstable and undergoes decomposition upon prolonged heating. Unlike cluster 1, heating the benzylidyne-capped cluster 3 with bpcd in either CH 2Cl 2 or 1,2-dichloroethane furnishes the thermally unstable mixed-metal cluster Co 2MoCp(η 5-indenyl)(CO) 5[μ 2,η 2,η 1-C(Ph)C C(PPh 2)C(O)CH 2C(O)](μ-PPh 2) ( 4) and the carbyne-bridged dinuclear compound CoMo(η 5-indenyl)(μ-CPh)(CO) 2(μ-bpcd)Cl ( 5) as the principal reaction products. Thermolysis of 3 with added bpcd in toluene gives 4 as the sole observed product. Compounds 2, 4, and 5 have been fully characterized in solution, and the solid-state structures of 2 and 5 have been established by X-ray crystallography. The structure of 2 consists of a triangular Co 2Mo core that is capped by the methylidyne group and that contains a bpcd ligand that bridges the two cobalt centers. The X-ray structure of 5 provides support for the partial fragmentation of the original cluster through the loss of a cobalt vertex and the abstraction of a chlorine atom from the chlorinated solvent. The presence of a bridging carbyne moiety that spans the Co–Mo vector and a bpcd ligand that is chelated to the cobalt center by the two phosphine groups and attached to the molybdenum center by the alkene π bond of the dione ring are confirmed. The reactivity differences exhibited by clusters 1 and 3 are discussed, and these data are briefly contrasted with that of the cyclopentadienyl counterpart PhCCo 2Mo(η 5-Cp)(CO) 8.

Stability and dynamics of vortex clusters in nonrotated Bose-Einstein condensates

We study stationary clusters of vortices and antivortices in dilute pancake-shaped Bose-Einstein condensates confined in nonrotating harmonic traps. Previous theoretical results on the stability properties of these topologically nontrivial excited states are seemingly contradicting. We clarify this situation by a systematic stability analysis. The energetic and dynamic stability of the clusters is determined from the corresponding elementary excitation spectra obtained by solving the Bogoliubov equations. Furthermore, we study the temporal evolution of the dynamically unstable clusters. The stability of the clusters and the characteristics of their destabilizing modes only depend on the effective strength of the interactions between particles and the trap anisotropy. For certain values of these parameters, there exist several dynamical instabilities, but we show that there are also regions in which some of the clusters are dynamically stable. Moreover, we observe that the dynamical instability of the clusters does not always imply their structural instability, and that for some dynamically unstable states annihilation of the vortices is followed by their regeneration, and revival of the cluster.

The combination of deconvolution and density functional theory for the mid-infrared vibrational spectra of stable and unstable rhodium carbonyl clusters

Geometrical optimization and frequency calculations on [HRh(CO) 4] were carried out using density functional theory methods with the B3LYP, PBE and B3PW91 functionals in conjunction with the LanL2DZ and DGDZVP basis sets. The accuracy of each calculation was verified by comparing the predicted and the experimentally obtained deconvoluted mid-infrared experimental C O stretching frequencies. The use of the density functional PBE with DGDZVP as the basis set was found to be the most accurate. The same method was then applied to [(C 2H 5)CORh(CO) 4], [Rh 2(CO) 6(μ-CO) 2], [Rh 4(CO) 9(μ-CO) 3] and [Rh 6(CO) 12(μ 3-CO) 4]. Again, vibrational spectral patterns and relative band intensities were in very good agreement with those experimentally observed after BTEM deconvolution. The only inconsistency was a constant shift in the predicted wavenumber assignments of ca. 1.5% for the terminal carbonyl stretching modes. In addition, the optimized geometries were also in good agreement with available X-ray structures of isolatable [Rh 4(CO) 9(μ-CO) 3] and [Rh 6(CO) 12(μ 3-CO) 4]. DFT not only proved to be a valuable tool in validating and confirming the structure of the reactive and unstable species but it also allowed better assignment of the observed spectra especially when vibrational modes were overlapping. The combination of advanced multi-component deconvolution, like band-target entropy minimization (BTEM), with DFT spectral prediction appears to have considerable potential for exploratory in situ studies of reactive rhodium carbonyl systems.